Within several applications it is required to transfer pharmaceuticals or medicaments into a fluid container such as an infusion bag. Usually such infusion bags are filled with a transport liquid such as saline solution or glucose solution in order to simplify the drug preparation of such an infusion bag. Infusion bags are generally equipped with an injection port to provide medicaments and a piercing port to extract the fluid from the infusion bag to an infusion system and thereafter usually to a patient. These pre-manufactured ports on the infusion bags make them less flexible for use together with other injection devices. Manufacturing fluid containers having predetermined injection and extraction ports is also complicated in the sense that it adds manufacturing steps to the manufacturing of the fluid container itself.
One way of partly overcoming these drawbacks is described in the publication of WO 94/13247. The document describes a valve device comprising a valve body with a barrier membrane and a surrounding portion. The valve device has an adhesive surface located at the underside of the valve body to attach the valve body to the surface of an infusion bag. The valve device is manufactured in one piece of the same material and its main purpose is to be applied and handled on the occasion of use while retaining aseptic conditions even by persons of impaired sight. However even for persons with good sight the described solution may have drawbacks. Although allowing for any piercing member to be inserted through the membrane the document is completely silent about the drawback that the inserted piercing member may tear, rip, or even puncture the fluid container unless the user is cautious when handling the piercing member.
The publication of WO 82/03776 describes one way of trying to solve a related problem. The publication discloses a device for providing a barrier membrane to the surface of a flexible fluid container. The barrier membrane is adhered to the surface by an adhesive. Additionally the barrier membrane may be arranged with a flexible tube attached to a cylindrical casing. At the other end of the tube, the tube may be tightly connected to a holder for a hollow syringe needle. The syringe needle is surrounded by the tube which is slideable arranged to the syringe needle and is further provided with an arresting shoulder. The arresting shoulder of the syringe needle is in turn connected to connection means of a conventional type for a liquid conduit. The length of the tube is adapted such that its rear end rests against the holder of the syringe needle. When the needle is inserted the tube will also be inserted into the fluid container for as far as the arresting shoulder allows. The described solution provides for a rather complicated mechanism having moving parts for introducing or withdrawing a liquid into a flexible fluid container. There is a need for simpler solutions which maintain or even improve the safety of the process.